Degenerative osteoarthritis (“arthritis”), a painful joint disorder, is caused by fragments of bone, articular cartilage, and calcium pyrophosphate crystals that form on and/or adhere to the interior surfaces of an affected joint in the body. The fragments irritate and inflame the joint, causing discomfort.
There are a number of treatments for arthritis. One such treatment uses an anti-inflammatory medicine, such as ibuprofen, to reduce swelling within the joint. Although such treatment may relieve the symptoms of arthritis, it does not treat the cause of the inflammation (i.e., the fragments). Accordingly, arthroscopic surgery often is necessary in more severe cases to physically remove the fragments from within the joint.
One common arthroscopic fragment removal treatment, tidal lavage, employs an irrigation inflow cannula to provide a steady flow of irrigation liquid into the joint, and an irrigation outflow cannula to remove the irrigation liquid from the joint. Steady flow of liquid through the joint is intended to flush some of the fragments from the interior joint surfaces through the outflow irrigation cannula. The procedure, however, does not forcefully remove the fragments, consequently leaving some fragments lodged in the joint. The remaining fragments may continue to irritate and inflame the joint. Accordingly, a fragment removal treatment that more forcefully removes the fragments often is necessary.
One known forceful fragment removal procedure employs a hand-held, motor driven, metal instrument such as, for example, an arthroscopic shaver device. Although such motor driven devices may remove many fragments that are not removable with tidal lavage, they present a risk of trauma and further damage to the interior surfaces of the joint. Another problem with motor driven instruments is that they may be relatively ineffective for removing very small fragments that cannot be readily viewed by an arthroscope.
It therefore would be desirable to provide an arthroscopic irrigation device and technique to effectively and safely remove arthritis causing fragments from within a joint.